Caption: Pest control in Panama. Man spraying a wetland area with oil to prevent mosquito larvae living in the water. Photographed in Panama between 1890 and 1925. Pest control efforts in Panama during this period included attempts to control mosquitos to prevent malaria and yellow fever in the workers building the Panama Canal (1904-1914). French efforts to build the Canal had failed in the 1880s due to outbreaks of disease, but by the time of the US construction it was known that mosquitoes were responsible for spreading such diseases.